The goal of this grant is to use electrophysiological measures to characterize abnormalities in gating and timing in the autistic brain. The motivation for this research project derives from findings and models in autism of increased excitation/inhibition ratios, increased brain and white matter volume and altered connectivity. These changes, alone and in combination, have the potential to alter the intensity, timing and integration of signaling at multiple stages of processing. These signaling problems can potentially lead to the autistic behavioral phenotype through cognitive processing abnormalities including the hyperspecificity/overselectivity of autism, as well as to such features of autism as sensory processing abnormalities, seizures, and anxiety. We believe that characterizing abnormalities related to gating and timing phenomena may lead to the development of an electrophysiological battery that can be utilized for early diagnosis, prognosis and subtyping of autism, as well as the tracking of treatment efficacy.